Better use the call RfcOpenEx.

The following function opens an RFC connection.

RFC_HANDLE  SAP_API  RfcOpenExtV3(char* destination,
  RFC_MODE  mode,
  char*  hostname,
  int sysnr,
  char*  gateway_host,
  char*  gateway_service,
  char*  client,
  char*  user,
  char*  password,
  char*  language,
  int trace
  RFC_INT   use_load_balancing,
  char * lb_host,
  char * lb_system_name
  char * lb_group
  RFC_INT   use_sapgui);

All parameters are passed as single fields (using RFC_MODE).

The following parameters are always needed in this call: RFC_MODE mode and SAP logon information: client, user, password, language, trace, and use_sapgui.

The following parameters are necessary, depending on RFC_MODE:

·        RFC_MODE_CPIC:

Ў        destination must be defined

Ў        gateway-host and gateway_service can be defined

Ў        sideinfo is necessary.


Ў        use_load_balancing is 0 (OFF)

§         destination is not NULL:

gateway_host, gateway_service, hostname and sysnr can be defined. sideinfo is necessary.

§         destination is NULL:

gateway_host and gateway_service can be defined. hostname and sysnr must be defined.

Ў        use_load_balancing is 1 (ON)

destination, gateway_host, gateway_service, hostname and sysnr will not be evaluated.

lb_host and lb_system_name must be defined. If lb_group is NULL, the group ‘PUBLIC’ will be used.

use_sapgui and ABAP-Debug are not available with R/2.

This function is defined in SAPRFC.H.

Return Values:

·        Returns a handle to the RFC connection (RFC_HANDLE) or

·        Returns RFC_HANDLE_NULL

Function Parameters:

·        destination

name of destination or NULL

·        mode

connection mode (RFC_MODE)

·        hostname

hostname of target system or NULL

·        sysnr

system number (0-99)

·        gateway_host

gateway hostname or NULL

·        gateway_service

gateway service or NULL

·        client

signon data: client

·        user

signon data: user

·        password

signon data: password

·        language

signon data: language

·        trace

trace (OFF/ON/ABAP-DEBUG or also trace ON and ABAP-DEBUG: 0/1/2/3)

·        use_load_balancing

using load balancing feature (OFF/ON/0/1)

·        lb_host

host name of the ‘message server’

·        lb_system_name

name of the target system (e.g. C11)

·        lb_group

application server group or NULL for PUBLIC

·        use_sapgui

using sapgui to display SAP dynpros and graphics (OFF/ON: 0/1)

See also RfcOpen and RFC_OPTIONS.